Printed electronics - the big opportunity

In less than 20 years from now, it is reckoned that the total annual printed electronics market will be worth some $300 billion. In other words, it will be almost twice the size of the silicon chip industry today.

The reasoning behind this is that the technology has the potential to go far beyond providing a cheap alternative to the silicon chip. In fact, over the last couple of years, the focus of printed electronics has extended from displays, electronic paper and thin film transistor circuits to encompass lighting, sensors, batteries and even actuators.

So what? could well be your response. What on earth has this to do with the converting industry? The answer is that it could prove very significant for those prepared to take up the challenge since it is generally recognized that the printing of disposable electronic devices on low cost flexible substrates is where the printed electronics action will be in the future. In other words, a process that is similar to that being carried out by sections of the packaging industry today.

Although originally the main emphasis was on using digital inkjet technology, increasingly attention is turning to more traditional printing processes such as gravure, flexo and offset, due to their ability to offer high volume, low cost production. Another main benefit is that, whereas the silicon chip usually needs to be connected to other discrete components, which adds cost and can decrease reliability, it is possible to print all of these components in one or two press passes using similar materials and the same or similar equipment.

For example, in their development of printed electronics, the University of California, VTT Technology, Konarka, PolyIC and Paralec are all using or at least favour gravure printing, while Thin Film Electronics, in Sweden, has successfully used flexo and spin coating to print ferro-electric memories. In addition, Motorola has reported that it has produced over five miles of printed transistor circuits using reel-to-reel equipment.

And potential applications are enormous. Being lightweight, rugged and mechanically flexible, products range from RFID tags and smart shelf labelling to billboard size electronic displays, solar cells, lighting and sensors, as well as for computer/mobile phone displays, signage and posters.

However, before you become too excited about the prospect, it has to be said that it is still early days for the technology. But, as was reported at the Printed Electronics Europe 06 conference and exhibition held recently at Churchill College, Cambridge, the technology is beginning to move from the laboratory to the trialing stage.

OK, the title of the conference – ‘The next stage: commercialization of printed electronics’ – could be said to be somewhat premature and mass production is still some way off. When it comes to specialist areas, there are now companies out there that are beginning to commercialize their technology and a few are even making money. In fact, the conference organizer, IDTechEx, an independent strategic analyst company focusing on printed electronics, reported that in under 10 years, the organic light emitting diode (OLED) display market will be worth some $8 billion, as will that for logic/memory devices, due to the wide range of potential applications.

One of the largest potential markets for mass produced printed electronics is chipless RFID tags, due to the fact that they can be printed directly on products and packaging. Indeed, IDTechEx regards the market as an opportunity for printed electronics to move into the ‘big time’, since it could replace some 10 trillion bar codes used each year.

However, currently, there is a major constraint and that is the cost, a point made by a number of speakers at the conference. In fact, IDTechEx reckons that the cost will have to come down to at least one cent if not lower: companies such as Coca Cola and Unilever have said that at one cent they would start looking at tagging everything.

According to German based PolyIC, EPC RFID labels will not be available until 2008-10. So far, the company has developed a multi bit 13.56 MHz RFID chip and plans to sell a 16 bit RFID label as an anti counterfeiting product next year - including a version that uses a light as a safe/unsafe indicator. In addition, the company also produces chipless transistor circuits on flexible substrates using flexo, gravure and litho.

Another company involved in this market is Paralec with its self sintering silver inks. It reported at the conference that, so far, three manufacturers have switched their RFID antenna printing to three micron gravure using the ink. In fact, 30 to 40 per cent of RFID pallet and case labels reaching Wal-Mart incorporate antennae printed with Paralec’s ink. Flexo 3.5 micron layers are also an option with these inks.

Latest developments

Not surprisingly, with such large potential markets, a broadening range and number of companies are becoming involved in printed electronics, including many new start-ups. One such company, which was represented at the conference, is UK based Novalia. It was set up in October, last year, to develop printed electronic applications based on high volume printing, patterning and deposition processes, in the belief that it is essential to work with existing manufacturers and their facilities.

Its first project involved creating an interactive low cost trading card game which is ‘playground ready’ since it does not require a bulk reader or computer. This was achieved by flexo printing conductive tracks along the edge of the card, while the ‘master’ game card consists of a thin battery, flex circuit and LEDs. This enables it to compare the cards and determine the ‘winner’. Although the product has yet to go into production, Novalia reckons that the cost of printing the silver tracks would be £0.005 and the cost of manufacturing the ‘master’ card £0.80, mainly due to the cost of the thin battery.

As well as applications, significant progress is being made when it comes to the technology itself. For example, it is now possible with printed electronics to exceed the capabilities of conventional amorphous silicon. At least, this has been achieved in the laboratory and is expected to be at a commercial stage in some 18 months.

Many of the printed electronics developments are occurring in Japan, where numerous companies have filed small memory size patents. These include Dainippon Printing, which is seeking to print electronic circuits as part of its packaging operations. The same goes for Toppan Printing, which has launched what it calls audio paper. This is 0.75 mm thick and has a lamina flexible speaker plus a printed battery licensed from Power Paper.

So far, the substrate has been used in greetings cards, as promotional give-aways and on some packaging, including high value items such as perfume. In this instance, it enables the purchaser to record a message which can be played back by the receiver of the perfume.

Interestingly, the University of Tokyo has developed actuators that are polymer based and are driven by organic transistors. They are initially being used for a Braille display that allows a message to be punched in and changed. However, the display is only 1mm thick, weighs a few grammes and can be rolled up, thus providing the opportunity for many other applications.

Asia is also leading the way when it comes to OLED displays. Currently, the main emphasis here is to make the displays larger, cheaper and brighter while consuming less power. For example, Samsung, in Korea, which has licensed OLED display technology from Kodak, has invested some $500M in the last year to enable it to mass produce OLED displays. The facility is due to start up by the third quarter of this year.

Samsung hopes to ship 20M units in 2007 and 50M by 2008. It is also understood that the company is looking into how these displays can be printed.

Indeed, the potential size of the printed electronics market is enormous, while the applications are only limited by your imagination. Most importantly of all, the converting industry with its expertise and the facilities is ideally placed to take advantage.